ENGINEER RESEARCH AND DEVELOPMENT CENTER HANOVER NH HANOVER United States
Increasing temperatures and changes in precipitation associated with climate change are expected to have increasing impacts on the contiguous United States in the coming decades, including impacts on military training and outdoor activities in general. This work used projections of daily temperature and precipitation from multiple global climate model projections to calculate the days with high heat and drought indices, extreme high- and low temperature and precipitation event days, and heating and cooling degree-day indices. The heat stress index the wet bulb black globe temperature, or WBGT and Keetch-Byram drought index are calculated from climate model projections from 1950-1999 and 2070-2099, and compared to projections calculated from observed weather data for stations across the contiguous United States. Results showed that significant increases are projected across the southern United States for the days in the high heat category above 32 C 90 F. The higher humidity of the southeastern United States contributes to high WBGT as well, while the air temperatures are greatest in the southwest. These projected impacts can be characterized as widespread and severe for large portions of the United States, with expected impacts to military planning, public health and safety, and natural resource management.